Sinusitis is a condition affecting over 35 million Americans, and similarly large populations in the rest of the developed world. Sinusitis occurs when one or more of the four paired sinus cavities (i.e., maxillary, ethmoid, frontal, sphenoid) becomes obstructed. Normally the sinus cavities, each of which are lined by mucosa, produce mucous which is then moved by beating cilia from the sinus cavity out to the nasal cavity and down the throat. The combined sinuses produce approximately one liter of mucous daily, so the effective transport of this mucous is important to sinus health.
Each sinus cavity has an opening into the nasal passage called an ostium. When the mucosa of one or more of the ostia or regions near the ostia become inflamed, the egress of mucous is interrupted, setting the stage for an infection and/or inflammation of the sinus cavity, i.e., sinusitis. Infection/inflammations of the maxillary with or without the ethmoid sinuses make up the vast majority of cases of sinusitis, with far fewer cases involving the sphenoids and frontals. Though many instances of sinusitis may be treatable with appropriate medicates, in some cases sinusitis persists for months or more, a condition called chronic sinusitis, and may not respond to medical therapy. Some patients are also prone to multiple episodes of sinusitis in a given period of time, a condition called recurrent sinusitis.
Balloon dilation has been applied to treat constricted sinus passageways for the treatment of sinusitis. These balloon dilation devices typically involve the use of an inflatable balloon located at the distal end of a catheter (a balloon catheter). Generally, the inflatable balloon is inserted into the constricted sinus passageway in a deflated state. The balloon is then expanded to open or reduce the degree of constriction in the sinus passageway being treated. A variety of devices (inflation devices) have been used to inflate and deflate the inflatable balloon located on the catheters. Many of these devices used in these treatments have been bulky and cumbersome to use. Often an assistant to the physician is utilized to perform the inflating/deflating of the balloon catheter, as the overall systems include multiple components necessitating multiple operators working in conjunction with one another.
Existing inflation devices typically include a rather large volume syringe having a barrel that is filled with an incompressible fluid such as saline. The syringe includes a plunger assembly having a shaft portion that terminates at one end with a sealing member located within the syringe barrel. The sealing member is sealed (or acts as a seal) within the interior of the bore. The other end of the stem is typically secured to a depressor or the like that enables the user to actuate the syringe. The inflation devices also typically include a pressure gauge. The pressure gauge measures, indirectly, the pressure within the inflatable balloon. Pressure to the inflatable balloon is adjusted by the degree of insertion of the plunger assembly within the barrel of the syringe. The pressure is indicated by the pressure gauge, and the user can adjust the pressure accordingly by relative movement of the plunger with the syringe barrel. A syringe having a large volume (and thus is large and bulky) is typically chosen to provide for adequate vacuum pressures that overcome the volume compliance of the pressure gauge, and to a lesser extent the volume compliance of the remainder of the closed system including the balloon dilation catheter itself. As a result, existing inflation devices are bulky and cumbersome to work with, requiring a dedicated operator just for its operation. Thus, medical interventional procedures that require use of balloon dilation may require additional personnel to operate the balloon inflation device in addition to other interventional devices.
There thus is a need for an inflation device that would simplify the dilation of an expandable member such as a dilation balloon. Such a device should be more compact than existing inflation devices and enable a single user to operate the inflation device during inflation/deflation. Such a device and any system that would incorporate the device would be particularly useful and advantageous in procedures where the dilation balloon is used to dilate constricted spaces, particularly constricted spaces in the sinus cavities.